Differences in clinicopathological characteristics, treatment, and survival outcomes between older and younger breast cancer patients: A regional perspective.

Abstract

e18604 Background: In developing countries, breast cancer treatment outcomes may be uniquely affected by the tendency of breast cancer patients to develop the disease at a much younger age than the worldwide average. Contrarily, older patients tend to present with multiple comorbidities that complicate their outcomes and influence their treatment options and decisions. This study will be the first to investigate the dichotomies between older and young breast cancer patients in our region. Methods: The study was based on data collected from the cancer registry of our institution for breast cancer patients 65 years or older (n = 553), and patients 40 years or younger (n = 417) at time of diagnosis. Statistical models were used to investigate the associations between age groups, clinical characteristics and treatment outcomes. Results: A total of 970 patients were included in the final analysis. Compared to younger patients, older ones were more frequently diagnosed with distal metastasis; 20.6% compared to 15.1%, p =0.028. However, among patients with non-metastatic disease, younger ones tended to have more aggressive pathological features, including positive axillary lymph nodes (73.2% vs. 55.6%, p< 0.001), T-3/4 (28.2% vs. 13.8%, p< 0.001) and HER2-positive disease (29.3% vs. 16.3%, p< 0.001). A higher percentage of patients from the young cohort underwent surgery (85.4%) when compared to the older group (74.9%), p< 0.001. More patients in the older group had mastectomy than did younger patients (67.5% versus 40.2%, p< 0.001), while breast conserving surgery (BCS) was performed on almost a third in each cohort, p= 0.245. Skin-sparing, with or without, nipple-sparing mastectomies (SSMs) along with breast reconstruction surgery were more frequently performed on younger patients than they were on the older patients. After a median follow-up of 59 months for the younger patients and 45 months for the older ones, the 5-year OS rate of the older patients was 67.6% compared to 72.1% for the younger patients, p= 0.035. However, the 5-year DFS rates of the two cohorts were not statistically different at 63.9% for the older group and 60.7% for the young patients, p= 0.31. The survival of patients with non-metastatic disease was also compared among both groups; the 5-year OS among the younger patients was significantly higher (83.6% compared to 78.8% among the older patients, p= 0.046). Survival was better among the younger patients across many clinical and pathological characteristics. Conclusions: Younger patients with breast cancer present with worse clinical and pathological features, albeit a better OS rate. The difference in DFS between the two groups was insignificant, suggesting that older women were more likely to die from non-cancer related causes.